Effect of multiple doses of nedocromil sodium given after allergen inhalation in asthma

Twelve subjects with asthma took part in a placebo-controlled crossover study designed to investigate whether nedocromil sodium given after the occurrence of the early-phase asthmatic reaction to allergen has an effect on the late-phase response and the associated increase in airway responsiveness.

The treatments were administered four times at 4-hour intervals at a dose of 4 mg, with the first dose given 1 hour after the last allergen challenge. Changes in airway caliber were monitored for 15 hours after allergen exposure by measuring forced expiratory volume in 1 second hourly. Airway responsiveness to methacholine was determined 24 hours before and 24 hours after allergen challenge.

Nedocromil sodium failed to reduce significantly the maximum late fall in forced expiratory volume in 1 second as compared with placebo but delayed its occurrence by 1.5 hours (p = 0.05). Nonspecific airway responsiveness to methacholine was similarly increased after allergen challenge when patients received nedocromil sodium and placebo. No unusual events were reported during the study period by any patient. These results indicate that nedocromil sodium is not able to interrupt the ongoing cascade of inflammatory events leading to the late-phase reaction and the associated increase in airway responsiveness.

In allergic asthma, nedocromil can be used only as a preventive treatment.